Summary of Significant Accounting Policies Product Warranty Liability (Details) (USD $) In Millions, except Per Share data	3 Months Ended				9 Months Ended
	Jul. 31, 2011	Apr. 30, 2011		Jul. 31, 2010	Jul. 31, 2011		Jul. 31, 2010		Oct. 31, 2010
Accrued Product Warranty And Deferred Warranty Revenue, Standard And Extended Warranty Programs, Roll Forward:
Accrued product warranty and deferred warranty revenue, at beginning of period					$ 506		$ 492
Cost accrued and revenues deferred					281		175
Adjustments to pre-existing warranties	30	27	[1]	25	66	[1]	34	[1]
Payments and revenues recognized					(288)		(218)
Accrued product warranty and deferred warranty revenue, at end of period	565			483	565		483
Less: Current portion	254			244	254		244
Noncurrent accrued product warranty and deferred warranty revenue	311			239	311		239
Adjustments to pre-existing warranties, per diluted share	$ 0.39	$ 0.34	[1]	$ 0.34
Extended Warranty Program:
Extended warranty program deferred revenue	220				220				167
Revenue recognized under extended warranty programs	$ 13			$ 11	$ 39		$ 34

[1] Adjustments to pre-existing warranties reflect changes in our estimate of warranty costs for products sold in prior periods. Such adjustments typically occur when claims experience deviates from historic and expected trends and are also impacted by authorized field campaigns. In the second quarter of 2011, we recorded adjustments for changes in estimates of $27 million, or $0.34 per diluted share.